fuse: clean up execute permission checking

Define a new function fuse_refresh_attributes() that conditionally refreshes
the attributes based on the validity timeout.

In fuse_permission() only refresh the attributes for checking the execute bits
if necessary.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 31 insertions, 18 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 8ea4ea13ec5..d1acab93133 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -695,6 +695,20 @@ static int fuse_do_getattr(struct inode *inode)
 }
 
 /*
+ * Check if attributes are still valid, and if not send a GETATTR
+ * request to refresh them.
+ */
+static int fuse_refresh_attributes(struct inode *inode)
+{
+        struct fuse_inode *fi = get_fuse_inode(inode);
+
+        if (fi->i_time < get_jiffies_64())
+                return fuse_do_getattr(inode);
+        else
+                return 0;
+}
+
+/*
  * Calling into a user-controlled filesystem gives the filesystem
  * daemon ptrace-like capabilities over the requester process.  This
  * means, that the filesystem daemon is able to record the exact
@@ -770,7 +784,6 @@ static int fuse_access(struct inode *inode, int mask)
 static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
 {
         struct fuse_conn *fc = get_fuse_conn(inode);
-        struct fuse_inode *fi = get_fuse_inode(inode);
         bool refreshed = false;
         int err = 0;
 
@@ -778,12 +791,11 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
                 return -EACCES;
 
         /*
-         * If attributes are needed, but are stale, refresh them
-         * before proceeding
+         * If attributes are needed, refresh them before proceeding
          */
-        if (((fc->flags & FUSE_DEFAULT_PERMISSIONS) || (mask & MAY_EXEC)) &&
-            fi->i_time < get_jiffies_64()) {
-                err = fuse_do_getattr(inode);
+        if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
+            ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
+                err = fuse_refresh_attributes(inode);
                 if (err)
                         return err;
 
@@ -806,14 +818,17 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
                    exist.  So if permissions are revoked this won't be
                    noticed immediately, only after the attribute
                    timeout has expired */
-
-        } else {
-                int mode = inode->i_mode;
-                if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
-                        return -EACCES;
-
-                if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR)))
-                        return fuse_access(inode, mask);
+        } else if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR))) {
+                err = fuse_access(inode, mask);
+        } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
+                if (!(inode->i_mode & S_IXUGO)) {
+                        if (refreshed)
+                                return -EACCES;
+
+                        err = fuse_do_getattr(inode);
+                        if (!err && !(inode->i_mode & S_IXUGO))
+                                return -EACCES;
+                }
         }
         return err;
 }
@@ -1046,14 +1061,12 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
         struct inode *inode = entry->d_inode;
         struct fuse_inode *fi = get_fuse_inode(inode);
         struct fuse_conn *fc = get_fuse_conn(inode);
-        int err = 0;
+        int err;
 
         if (!fuse_allow_task(fc, current))
                 return -EACCES;
 
-        if (fi->i_time < get_jiffies_64())
-                err = fuse_do_getattr(inode);
-
+        err = fuse_refresh_attributes(inode);
         if (!err) {
                 generic_fillattr(inode, stat);
                 stat->mode = fi->orig_i_mode;